Improper initialization in Linux kernel - CVE-2026-90094

Vulnerability identifier: #VU151382

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90094

CWE-ID: CWE-665

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause MTE store-only tag check state to leak into another task.

The vulnerability exists due to improper restoration of SCTLR_EL1.TCSO0 state in arm64 context switching when switching from a task that has opted into MTE store-only tag check mode. A local user can opt into MTE store-only tag check mode and trigger a context switch to cause MTE store-only tag check state to leak into another task.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/00a73ce437e27fdc636a5ede445a4a491e01788d
• https://git.kernel.org/stable/c/2f10bc3ff24c91657887901c3235b803e5055f2b
• https://git.kernel.org/stable/c/b8f070ac3167595069feb1f794c127b805115645

• Improper initialization in Linux kernel include asm
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more